Performance of PET imaging for the localization of epileptogenic zone in patients with epilepsy: a meta-analysis

Objectives The aim of this meta-analysis was to estimate the clinical use value of 11 C-FMZ and 18 F-FDG in PET for the localization of epileptogenic zone and to provide evidence for practitioners’ clinical decision-making. Methods We searched PubMed and Embase in a time frame from inception to May 31, 2020. Studies utilizing FMZ or FDG-PET or FDG-PET/MRI used in patients with epilepsy, with EEG or surgical outcomes as the gold standard and corresponding outcomes such as concordance rates of PET or PET/MRI scan compared with reference standard, absolute numbers of participants with true-positive (TP), false-positive (FP), true-negative (TN), and false-negative (FN) results in FDG or FMZ PET. Pooled concordance rates, overall sensitivity, and specificity of 11 C-FMZ-PET and 18 F-FDG-PET were calculated. Results In total, 44 studies met the inclusion criteria. The pooled concordance rates of FDG-PET, FMZ-PET, and FDG-PET/MRI coregistration compared with reference standard were 0.67 (95% CI: 0.60–0.73), 0.75 (95% CI: 0.57–0.93), and 0.93 (95% CI: 0.89–0.97), respectively. The concordance rate of 18 F-FDG-PET in patients with temporal lobe epilepsy (TLE) was 0.79 (0.63; 0.92). The overall sensitivity and specificity of 18 F-FDG-PET were 0.66 (95% CI: 0.58–0.73) and 0.71 (95% CI: 0.63–0.78), respectively. 11 C-FMZ-PET displayed an overall sensitivity of 0.62 (95% CI: 0.49–0.73) and specificity of 0.73 (95% CI: 0.59–0.84). Conclusions Both 11 C-FMZ PET and 18 F-FDG PET are the choice of modalities for the localization of epileptogenic zone, especially when coregistered with MRI. Key Points • 11 C-FMZ-PET may be more helpful than 18 F-FDG-PET in the localization of epilepsy foci. • Coregistration of FDG-PET and MRI is recommended in the localization of epileptogenic zone.